One of the more recent developments in the field of cigarette technology involves cigarettes which contain a non-tobacco fuel source which typically heats tobacco contained within a cigarette.
One problem encountered in producing such cigarettes is the availability of a suitable wrapper. The burning of tobacco in conventional cigarettes masks the odor of the burning wrapper used in conventional cigarettes. Because non-tobacco fueled cigarettes have little or no odor attributable to the combustion of the fuel element or tobacco, any odor resulting from the burning of the wrapper is highly noticeable. A suitable wrapper must, therefore, emit little if any aroma or smoke upon ignition of the cigarette, have the appearance of a conventional cigarette and provide adequate support once the cigarette is lit to contain the fuel source within the cigarette.
It is known in the art to add burn control agents to paper used with smoking products to control burn rate, ash formation and sidestream smoke emission. These agents may act to either retard or accelerate the burn rate of the paper. However, even though burn rate is controlled, paper treated with such burn control agents generally burns unless large amounts of burn control agents are added. This burning produces an unpleasant odor and transforms the cellulose into a non-cellulose ash. Alternatively, paper treated with large amounts of burn control agents is transformed by the heat into a cellulose char, and the emission of appreciable odor and smoke is eliminated. However, the char produced is typically a black or an aesthetically unacceptable dark color.
U.S. Pat. No. 4,453,553, teaches a wrapper treated with a burn retarding compound which produces a light grey or white ash. This wrapper is not acceptable because it burns emitting an odor and forming an ash which does not possess sufficient strength to contain the fuel source within the cigarette.
Another example is disclosed in U.S. Pat. No. 4,779,631. This wrapper, has the disadvantage of providing a non-uniform length of ash, the length of which varies with the puffing strength of the smoker, produces an aroma which is irritating and detrimental to room aroma, and does not provide uniform delivery to the smoker.
Thus, a need exists in the art for a wrapper for use with smoking products which does not produce a noticeable aroma, does not burn out to form an ash incapable of containing the fuel source, and does not produce a variable length char or char having an aesthetically unacceptable color, and which provides uniform delivery to the smoker.